The board of trustees shall manage and direct the affairs of this division. It shall have the exclusive right to interpret this division and its provisions including but not limited to any benefit or claim for benefit hereunder, determination of creditable service, final average compensation, eligibility and termination of membership. The board shall consist of nine members, including the director of human resources and director of finance. Seven shall be appointed by the mayor as follows: 1. One shall be a retired member of the system 2. Four, other than the foregoing, shall be recognized business and/or civic leaders with financial backgrounds, such as investments, management of employees benefit plans, who are not employees of the city. At the mayor’s option, one of this group may be a city council person with a financial background who shall serve as an ex-officio member of the board with a right to vote. 3. Two shall be active employees and members of the retirement system as recommended by the union.